Overview

The soulnote D/A Converter D-3 is the flagship D/A converter developed by the Japanese company soulnote. It features a dual-monaural configuration with a total of four ES9038PRO chips, two for each channel. Characterized by its high-current output and low-jitter performance, it has a unique design that operates only in conjunction with the external clock generator X-3 (sold separately). The D-3 itself is priced at 1,650,000 JPY, and the mandatory X-3 costs 748,000 JPY, bringing the total system price to 2,398,000 JPY (including tax), placing it in the ultra-high-end price segment.

Scientific Validity

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The scientific validity of the D-3 is rated very highly. Its core DAC chip, the ES9038PRO, on its own, boasts performance that far exceeds the limits of human hearing, achieving a “transparent level” with a THD+N of -122dB and a dynamic range of 140dB (in mono mode). This allows it to achieve ideal figures in almost all measurement categories related to sound quality, such as frequency response, S/N ratio, and distortion. While it is scientifically questionable whether soulnote’s touted high-current output and low-jitter performance provide audible improvements beyond this transparent level, there is no doubt that its basic performance is extremely faithful to the master sound source.

Technology Level

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The technical implementation of the D-3 is commendable. The design is sophisticated, featuring a dual-monaural configuration that electrically and physically separates the left and right channels, three independent high-capacity toroidal transformers, and glass-sealed reed relays for signal switching. The design philosophy of bypassing the DAC chip’s asynchronous sample rate converter (ASRC) and synchronizing it with an external clock is also original. However, the foundation of the sound quality is the off-the-shelf ES9038PRO chip, and it is unclear whether these additional technologies contribute significantly to improved measured performance. Since comparable performance can be achieved with simpler circuits, the technology level is assessed as industry average.

Cost-Performance

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The cost-performance of the D-3 is extremely poor. As a point of comparison, the Topping D90SE (retailing at 139,392 JPY) uses the same ES9038PRO chip and offers equivalent or superior measured performance. The D-3 system, including the mandatory X-3 clock generator, totals 2,398,000 JPY. The cost-performance calculation is “139,392 JPY ÷ 2,398,000 JPY ≈ 0.058,” which rounds to a score of 0.1. This means an alternative product exists that delivers equivalent or better basic performance for about 1/17th of the price. There is no objective performance difference to justify this price gap.

Reliability & Support

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Soulnote is a Japanese audio manufacturer with a good reputation for product reliability and support. As expected from a high-end device, meticulous craftsmanship and quality control can be anticipated, with appropriate warranty and repair services available domestically. However, the mandatory external clock configuration increases the points of failure and operational complexity compared to a standalone unit. Additionally, for an ultra-high-priced product, attention must be paid to the long-term availability of parts and support. While good by industry standards, the rating is slightly lowered to account for the design’s complexity.

Rationality of Design Philosophy

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The D-3’s design philosophy is questionable in terms of rationality. A design that cannot function without an external clock generator significantly impairs user convenience. Furthermore, the necessity for such an expensive and complex implementation for the ES9038PRO chip, which already possesses transparent-level performance on its own, is unclear. This approach runs counter to the direction of modern audio technology, which aims to achieve measurable performance improvements more cost-effectively and rationally. Since equivalent performance can be achieved with a combination of much cheaper general-purpose equipment, it is difficult to justify the device’s existence as a dedicated audio machine based on performance.

Advice

Careful judgment is recommended when considering the purchase of the D-3. While the luxurious build and unique design philosophy may satisfy a desire for ownership, objective performance evaluations show no clear difference from far cheaper products using the same DAC chip. With a budget of nearly 2.4 million JPY, one could build a top-tier system featuring a high-performance DAC like the Topping D90SE, combined with the best-in-class preamplifiers, power amplifiers, and speakers. For those purely in pursuit of sound quality improvement, it would be wiser to allocate the budget to optimizing the entire system. This product is best suited for enthusiasts who find special value in its brand and rarity.

(2025.7.22)